Heater for gases or vapors



May 22, 1951 E. STRUNK 2,554,130

HEATER FOR GASES 0R VAPORS Filed Dec. 5, 1944 v 5 Sheets-Sheet l EDWARD STRUNK 5 AZORNE? y 5 E. STIRUNK 2,554,130

HEATER FOR GASES 0R VAPORS Filed Dec. 5, 1944 5 Sheets-Sheet 2 Tic z.

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INVENTOR EDWARD STRUNK AITORNEYS y 22, 1951 E. STRUNK 2,554,130

HEATER FOR GASES OR VAPORS Filed Dec. 5, 1944 5 SheetsSheet 5 INVENTOR EDWARD STRUNK AT; ORNEYS May 22, 1951 E. STRUNK 2,554,130

HEATER FOR GASES OR VAPORS Filed Dec. 5, 1944 5 Sheets-Sheet 5 INVENTOR EDWARD STRUNK ATTORN EYS Patented May 22, 1951 u N l T EJD srAr Es PAT em: o r F LC E FOR GASES OR J'IV APOR ST Edward S'trunk; Phillips, 'Texi ais'si'g'nor tolPhillips Petroleum Company; a corporation ofa'Delaware ApplicationDecember 5, 1944," Se'ri'alNo. 566,740

3- Glaimsz- (Cl. 257-229) The" presentiinvention relates to a heater for gases or vapors and particularlya' heater'arranged to give optimum flow conditions with high heat transfer ratesand nominal pressure drop:

Furthermore, the heater is arranged to overcome the difficultiesnormallyintroducedby reason of thermal expansion of the tubes and head'- ers.

It is an object" of? the invention to provide a heater for gases and vaporsin which optimum flow conditions yielding'high heat transfer rates andnominal pressure drops are provided'for.

It is a further object of the inventiont'o provide such a heater in which, due to the arrangement of the tubes and headers andthe' mode of supporting them in a furnace, the difii'culti'es arising from thermal expansion are overcome.

It is a still further object of" the invention to provide such an arrangement in which the tube supportingsystem' is relatively simple and inex pensive of manufacture and readily installed in a normal type furnace.

Other'obj ect's'and'featuresof theinvention will be apparentwhen the following description is considered in connection with the annexed drawings in' which:

Figures 1 and 2 together comprise a vertical cross sectional view of a'heater'having a preferredembodiment of my invention installed therein;

Figure 3is afragmentary vertical cross section ofthefurnaceof-Figures 1 and2, the section being taken at right angles to that of the above mentioned figures;

Figuree is a" cross sectional view ofthe furnace taken on the plane of the line 4-4 of Figure 1 showing particularly the conformation of a single coil of the tube system of'my'invention;

Figure 5 is'a fragmentarycross" sectional View taken on the line 5-5 of Figure 4 and illustrating the mode of supporting the tube coils at one point in the circumference thereof Figure 6 is a cross sectional view of one of the headers showing. the mode of constructing the header aswell as the mode of inserting onerof-the tubes therein;

Figure 7 is a-fragmentary' elevational view, partiallyin section, likewiseshowing the mode of constructing and dividing one ofthe headers'into sections;

Figure 8 is an elevationof one of the supporting members for the: tube structure;

Figure Qisan elevation at-right anglesto-that ofFigure 8- likewise showing the mode of con-- structing' one of the tubesupportingjmembers;

ispositioned.

Figure10= is a topplan View of the member of- Figures Sand- 9';

Figurell isanexploded view of a supporting bracket together with links forming auniversal joint which is used in combination with the member of Figures- 8, 9 and 10 tosuspend the tubes from thefurnace walls;

Figure-12 is-averticalcross sectional viewillustrating schematicallythe arrangement" of a furnace" in" accordance with my invention; and

Figure 13 is a horizontal cross section on the plane of the line I-3- l-3 of Figure 12 particularly illustrating the conformation-of the tubes of the schematic furnace of Figure 12;

Referringnow tothe drawings and particularly toFigures l2and 13 -thereof; there is-shown there ina furnace I", having acombustion chamber 2 in which fuelfrom the nozzle 3 isburned, the products of combustion passing up the vertical stackina known manner. In the stack portion 4 of'the furnace the tube structure of" myinvention This tube structure comprises tubular-headei'sfi and a plurality of tubes B'which tubes are bent into circularformas seen particularly in Figure 13'and-are arranged with their axesp'ara-llel. As will beseenby reference particularly to Figure 12-the gases orvapors are-injected into the headers and tubes in any'knowh manner as by means of the pump- T, the headers being tubular and the tubes being arranged in circular formation. It will be seen that the optimum conditions for high heat transfer and low'pre'ssure drop are provided since this'tubular formation'of the headers together with this circular formation of" the tubular tubes eliminates sharp'bendsand reduces frictional losses:

Due to the fact that both pressure drop and rate of heatjtransfer from hot surfaces to gases are the function ofvelocity of flow, the size and length of the headers and the desirednum'ber of tubesand' size thereof maybe determined.

The materialentering the first header. 5flo'ws through the group of coils'comprising the three tubes designated 6a, 6b,, 6c and thence flows through these tubes in parallel to the second header which is located adjacent to and with its axisparallelt'o that? of" the first header, the gases orvapors'flowing into this second header riseupwardly and then flow, in a direction thelreverse offthat in the tubes 6a, 6b, to through tubes 622, 6e; 67 and to a third header Which is arranged paralleland adjacent to-the second header. In fact, the headers of a group,-i, e. the odd or even numbered headers may be on the same center line. This arrangementis continued through as many headers and tube sections as is necessary for the temperature conditions desired until the material is finally discharged through the discharge pipe 8 which is connected to the last header and leads to the point of utilization of the heated gases or vapors.

Thermal expansion in the apparatus, as may be readily seen, will be taken up by a change in diameter of the tube circles since each tube is free to expand and contract independently of all others. Furthermore, thermal expansion of the headers is provided for since the headers may expand longitudinally without altering conditions except that the spacing of the individual tubes is thereby changed. Since the headers may be relatively short it is clear that this small shift may be absorbed by the use of suitable hangers and supports.

The details of a preferred practical embodiment of the construction shown schematically and described above are illustrated in Figures 1 through 11. Referring now to those figures there is shown in Figures 1 and 2 a generally cylindrical furnace 9 which is lined with a thermal insulator E in the usual manner. This furnace is provided with normal type burners I I located at the bottom thereof and with a ceramic refractory fire box I2. Obviously, instead of supplying fuel burners I l the apparatus may utilize the exhaust of some other equipment.

The furnace is properly shaped to provide a rectangular portion l3 near the top thereof in which the economizer tubes l4 are located and these tubes may be utilized in the usual manner to preheat the fuel supply to the furnace or for any other heating of material which is desirable.

Fixed to the side walls of the furnace near the top thereof and at spaced points on the circumference are brackets l5 which brackets are illustrated in detail in Figure 11 and comprise a wall portion 16 together with outward extension I! and a downwardly extending pair of lugs l8.

Each such bracket is provided near the lower end of the lugs IS with a pair of holes l9 in which a pin may be inserted, this pin being adapted to hold the block 20 pivotally within the pair of lugs l8.

Block 20 is provided with pivot holes for the pin extending through holes l9, as well as for a pin extending at right angles thereto. Pivotally mounted on this pin are two links 2! which are provided at their lower ends with holes adapted to receive a second pin. Pivotally mounted between the links 2| is a second block 22 which is similar to the block 20 and provides means for pivotally supporting the second pair of links or bars 23. The structure above described constitutes a bracket from which depends a universal joint comprising the blocks 20 and 22 together with the links 2| and from this universal joint depend the bars or links 23 which bars, as will be hereinafter described, in turn support the tube suspending bars 24.

Referring now to Figures 8, 9 and it will be seen that the links 23 are slotted for a considerable portion of their length as indicated particularly at 25 and have inserted in the slots a tube supporting bar 24. The bar 24 is welded to the links 23 along the edges of the slot 25 as is particularly illustrated in Figure 10, the weld being shown at 26. In order to render the structure rigid the links 23 are joined together near the top by a plate 2'! which is welded to the top of the bar 24 and to the inner sides of the links 23.

As has been indicated the bars 24 extend downwardly from the universal joint comprising the members 20, 2|, 22 and 23, all mentioned above, and form supports for the various tubes which tubes are round in cross section and are bent into a circular form. The bars 24 are provided with holes at spaced intervals and thereby form supports for the tubes mentioned above, the tubes being passed through corresponding holes in the four downwardly extending bars which are spaced around the circumference of the furnace as described.

In addition the tubes are supported by means of a downwardly extending bar 28, this bar being supported at its upper end by means of the links 29 and pin 33 which links are in turn supported by a bar 3| which extends downwardly from an angle iron frame 32 supported outside the furnace on a framework of suitable construction (see Figures 1 and 5). It will be seen that the bar 3i and links 29 extend through a sloping portion of the upper furnace wall, the wall being provided with a sleeve 33 and the opening being packed with insulating material as is indicated particularly at 34. Bar 28 is guided for movement by means of the guides 35 (Figures 1 and 2) which are slotted and are fastened to the furnace wall and in the slots of which the bar 28 moves vertically and horizontally.

It will be seen that due to the articulation provided by the various links above mentioned the tubes 6 may expand to form coils of greater or lesser circumference in accordance with the thermal conditions in the furnace. The tubes are of course additionally supported by virtue of their connection to the headers la through if. The header sections la, b and 0 form one complete unit which is designated 33 while sections d, e and f are designated 3'1, Figures 1, 2 and 3.

Since the two headers are substantially identical a single description will sufiice. The header 36 is formed of the three tube sections "la, b and c and the mode of joining the tube sections and supporting them is indicated in Figures 6 and '7. Referring to these figures it will be seen that a circular plate 38 is arranged with the ends of the tube sections la and 1b abutting it on opposite sides the plate being of somewhat greater diameter than the tubes and extending slightly beyond the circumference thereof. Straps 39 are welded to the adjacent ends of the two tube sections as well as to the plate 38 and additionally plate 38 is welded to the ends of the tube sections. Thus a structure is provided in which the separate headers la, b and c are substantial- 1y a single structure and as such may be and are supported by suspension from the angle iron structure 43 which is indicated in Figure l and which is in turn supported from the sloping portion of the furnace walls in a manner to be described.

Where the headers 36 and 31 pass through the furnace wall sleeves are provided, these sleeves being packed with an insulating material such as asbestos rope. Although the headers may be supported in any convenient manner they have been shown as having a ring 4| welded thereto which ring hangs against a sleeve supported by the framework 40.

The header 36 is provided at its upper end with a flange 42 and is closed at its lower end as is indicated at 43. The header 3'! is closed at its upper end and provided with a flange at its lower end. Since these headers are suspended as above described it will be clear that they may expand longitudinally as is required by the thermal conditions-within the furnace: The flow of thegases or vapors through the headerand coilstructure will be as follows:

Into the header 36 and downwardly through section 1a,- through the five uppermost tubes 6 in parallel in a clockwise direction, and into the section 1d of header 31, downwardly through that headerv and thence in-parallel through the next lower fivetubest inacounterclockwise direction and into the section lbofhea-der 36, thence again. downwardly through. this header section and through: the thirdv group of: five tubesli in a clockwise direction to section 'le of header 3'2", thence again downwardly through this section and through the next lower group of five tubes 6 in parallel in a counterclockwise direction into section 1c of header 36 and thence downwardly through this header section and clockwise through the lowermost five tubes 6 and into section If of header 31 and thence downwardly and to the point of utilization.

It will be seen that in the tube and header construction above described there are no sharp bends and consequently the frictional losses are extremely small and the sizes and numbers of the tubes together with the sizes of the headers may be determined to give optimum flow conditions and thereby high heat transfer rates and nominal pressure drops. It will be further seen that due to the mode of articulation of the supports for the tubes as well as the mode of suspension of the headers thermal expansion and contraction may occur without any detrimental results. Thus the tube expansion is provided for by permitting an increase in the diameter of the circle into which the tubes are formed and header expansion is prepared for by the suspension of the headers in the manner described. Furthermore, since the supporting bars 24 and 28 are subject to contraction and expansion in substantially the same degree as the tubular headers 36 and 31 the coils are always substantially horizontal and since the combustion gases pass upwardly through the center of the cylinder formed by the various coils all parts of any coil are subjected to substantially the same temperature.

While I have described a preferred embodiment of my invention it is obvious that other embodiments and constructions may be adopted without departing from the spirit of my invention and, consequently, I desire to be limited not by the foregoing description but solely by the scope of the appended claims.

What is claimed is:

1. In a heater for gases or vapors, in combination, a generally cylindrical vessel, a pair of header tubes extending longitudinally of said vessel and positioned in parallel relation within a sector of 45 at the periphery of the vessel, means permitting longitudinal expansion and contraction of said headers, partitions in both of said headers arranged in staggered formation to define a series of compartments in each header, each such compartment in one header being positioned next to two such compartments in the other header, a series of longitudinally spaced tubes in said vessel, each tube extending, in a circular path, from one header to the other header and being closely spaced to the walls of said vessel throughout its length, each tube connecing a compartment in one header with an adjacent compartment in the other header, a plurality of supporting bars for said tubes extending longitudinally of said vessel, each bar having passages formed therein to receivethe respective tubes, a universal joint supporting-each bar from the vessel, and a plurality of longitudinally spaced guides each having a slottedportion en'- gageable with one of said bars to permit longitudinal or radial movement of said bar butto prevent tangential movement of said' bar; said headers and tubes being arranged to form an unobstructed path for a heating medium flowing about said headers and tubes.

2. In a heater'for gasesorvapors", in combination. a generally: cylindricalvessel, 2.; pair; of header tubes extending longitudinally ofisaids-vesrsel and positioned in parallel relation within a sector of 45 at the periphery of the vessel, the ends of said headers extending through openings at opposite ends of said vessel, a collar positioned outside the vessel encircling each header, means permitting longitudinal expansion and contraction of said headers, partitions in both of said headers arranged in staggered formation to define a series of compartments in each header, each such compartment in one header being p0- sitioned next to two such compartments in the other header, a series of longitudinally spaced tubes in said vessel, each tube extending, in a circular path, from one header to the other header and being closely spaced to the walls of said vessel throughout its length, each tube connecting a compartment in one header with an adjacent compartment in the other header, a plurality of supporting bars for said tubes extending longitudinally of said vessel, each bar having passages formed therein to receive the respective tubes, a universal joint supporting each bar from the vessel, and a plurality of longitudinally spaced guides each having a slotted portion engageable with one of said bars to permit longitudinal or radial movement of said bar but to prevent tangential movement of said bar, said headers and tubes being arranged to form an unobstructed path for a heating medium flowing about said headers and tubes.

3. In a heater for gases or vapors, in combination, a generally cylindrical vessel, a pair of header tubes extending longitudinally of said vessel and positioned in parallel relation within a sector of 45 at the periphery of the vessel, the ends of said headers extending through openings at opposite ends of said vessel, a collar positioned outside the vessel encircling each header, means permitting longitudinal expansion and contraction of said headers, partitions in both of said headers arranged in staggered formation to define a series of compartments in each header, each such compartment in one header being positioned next to two such compartments in the other header, a series of longitudinally spaced tubes in said vessel, each tube extending, in a circular path, from one header to the other header and being closely spaced to the walls of said vessel throughout its length, each tube connecting a compartment in one header with an adjacent compartment in the other header, a plurality of supporting bars for said tubes extending longitudinally of said vessel, each bar having passages formed therein to receive the respective tubes, a universal joint supporting each bar from the vessel, each universal joint including a bracket secured to the Wall of said vessel, a link supported by said bracket and movable with respect thereto in two mutually perpendicular planes, a second link secured to said first link and movable with respect thereto in two mutually perpendicular planes, said second link being secured to said bar, and a plurality of longitudinally spaced guides each having a slotted portion engageable with one of said bars to permit longitudinal or radial movement of said bar but to prevent tangential movement of said bar, said headers and tubes being arranged to form an unobstructed path for a heating medium flowing about said headers and tubes.

EDWARD STRUNK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Robbins July 1, 1879 Hooyman June 21, 1921 Price June 28, 1921 Wang June 26, 1934 Gazey Jan. 11, 1938 Parsons Jan. 18, 1938 FOREIGN PATENTS Country Date France Sept. 27, 1911 

